NOTE: These figures are carrier data reflecting nonstop bidirectional air trade
weight between the United States and other countries and, as such, will differ
from U.S. Census Bureau shipper-based merchandise trade statistics. Data for
airports, in this table also reflect actual U.S. airports, while data in tables
16, 17, 18, 19, and figure 9 reflect U.S. Customs ports at which air freight
activity occurred. Sometimes these Customs ports correspond to the actual airport
(e.g., JFK), while in other cases the U.S. Customs port refers to a broader
administrative area (e.g., Chicago, which includes O'Hare, Midway, and smaller
regional airports).

SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics,
Office of Airline Information data, May 2002.